The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Referring now to FIG. 1, a layered network model 10 is shown. Network model 10 includes a physical layer 12 that transmits and receives data over a communication channel 14. Examples of channel 14 include copper lines, fiber optic links, wireless links, and the like. Physical layer 12 can include an isolation sublayer 16; such as a transformer that isolates DC signals in channel 14 from other sublayers of physical layer 12. An amplification sublayer 18 amplifies signals that are received from channel 14 and amplifies signals that are transmitted onto channel 14. A filtering sublayer 20 communicates with amplification sublayer 18 and isolates signals of interest from noise and/or other signals that may appear on channel 14. An analog to digital conversion sublayer 22 converts data between a digital format that is employed by the other layers of network model 10 and an analog format that is employed by channel 14. The isolation sublayer 16 may pose limitations to the bandwidth through physical layer 12.